Résumé
The prostate specific antigen is commonly used as a preliminary tool to investigate men with lower urinary tract symptoms and prostatic enlargement evident by ultrasound scan. In the practice a high prostate specific antigen level is commonly used as predictor of prostatic cancer. A cross-sectional study was conducted at Omdurman Military hospital during the period from January 2011 to January 2012 to assess the validity of prostate specific antigen as single tool to diagnose prostatic cancer in our local population It included all male patients with lower urinary tract symptoms and proved to have prostatic enlargement by ultrasound. Prostate specific antigen levels were measured before digital rectal examination [DRE]. Trans-rectal biopsy was performed when the PSA level was over 4 ng and or abnormal DRE. The study included 192 patients, their mean age +/- SEM was 65.71 +/- 0.71 years [range, 32-95 years]. The mean PSA was 17.51241 +/- 1.98 [range, 0.002-125 ng/ml]. The sensitivity and specificity [%] of PSA level < 4 ng/ml to detect BPH were 96.6 and 37.7 respectively. The sensitivity and specificity of PSA level to detect cancer were 9.8 and 12.2 respectively for PSA ranging from 4 to 9 ng/ml, and 82.9 and 71.5 for PSA levels > 9 ng/ml respectively. When combining PSA, DRE and biopsy the sensitivity and specificity for cancer detection increased to 91.6% and 73.4% respectively. In conclusion the prostate specific antigen alone cannot be used as an effective diagnostic tool for diagnosis of prostate carcinoma due to its low sensitivity and specificity